Larvicidal composite alginate hydrogel combined with a Pickering emulsion of essential oil

"Partner" cellulose gel with "dialysis" function: Achieve the integration of filtration-enrichment-SERS detection

Hydrogel and aerogel materials have garnered significant attention in constructing effective surface-enhanced Raman spectroscopy (SERS) substrates due to their excellent adsorption capabilities, high specific surface area, and abundant chemical groups. However, in liquids with complex compositions, non-specific adsorption of macromolecules can lead to surface scaling and pore clogging of the substrate material, limiting the selective enrichment and SERS detection of target molecules. To address this, an innovative aerogel-chimeric hydrogel material (CH@S-CNF/SA/Ag NPs) was developed. The aerogel component, with its high specific surface area and electronegative properties, functions as a SERS "chip" for adsorption and detection of target molecules. Simultaneously, the mesoporous structure of the hydrogel "shell" effectively filters macromolecules from the solution. These CH@S-CNF/SA/Ag NPs were utilized as SERS substrate materials for detecting urine from healthy individuals and patients with chronic kidney disease stage 5 (CKD5). When combined with machine learning algorithms, the detection accuracy reached 99.50%. This work represents a significant advancement in the specific adsorption and SERS detection of small molecules in complex biological samples such as urine and blood.

Extract toolkit for essential oils: State of the art, trends, and challenges

Plant essential oils have a wide range of applications including cosmetics, food, leather, and textiles. Traditional methods employed for essential oils extraction suffer from several drawbacks, which have escalated into a major bottleneck for industrial applications. To circumvent the limitations, various innovative and eco-friendly technologies have emerged for the extraction of essential oils, such as ultrasound-assisted extraction, pulsed electrical-assisted extraction, ohmic-assisted technology, supercritical fluid extraction, and solvent-free microwave extraction. These cutting-edge technologies provide notable advantages over traditional methods in terms of extraction efficiency, environmental safety, and product quality enhancement. This review highlights the advantage of these innovative techniques, with a particular focus on their ability to enhance the yield and antioxidant activity of essential oils while simultaneously reducing energy consumption. Additionally, the mechanisms of these new and eco-friendly extraction methods are thoroughly discussed. This review provides valuable insights into the advancements in essential oils extraction.

Multifunctional gelatin nanoparticle stabilized-Pickering emulsion hydrogel based on dextran and amikacin with controlled drug release and enhanced antibacterial capability for promoting infected wound healing

Plant essential oils possess broad-spectral antimicrobial property, but the applications are impeded by their insolubility in water, extreme volatility, and strong irritation. Nanoparticle-stabilized emulsion (Pickering emulsion) gels are colloidal systems with ability to accommodate two immiscible phases in one system. The thick adsorption nanoparticle layers and the cross-linked networks in continuous phase could provide protective barriers for antibacterial oil and achieve on-demand controlled release. An emulsion hydrogel templated from gelatin nanoparticle-stabilized emulsion is one-pot constructed by conducting a tunable cross-linking process between oxidized dextran (Odex) and amikacin in the continuous phase and concomitantly trapping tea tree essential oil (TO) droplets in the three-dimensional network. The resulted emulsion hydrogel presents tunable gelation time, adequate mechanical strength, fascinating injectability, and self-healing capability. It is pH-responsiveness and presents controlled release of amikacin and TO, exhibiting a long-term bacteriostasis of 144 h. The emulsion hydrogel facilitates the outstanding wound healing efficiency in 14 days (95.2 ± 0.8 % of wound closure), accompanied with enhanced collagen deposition and angiogenic activities. The incorporation of TO into emulsion hydrogel system reduced its irritation and improved its biosafety, showing potential application in bacteria inhibition even as implants in vivo.

Natural Polymer-Based Graphene Oxide Bio-nanocomposite Hydrogel Beads: Superstructures with Advanced Potentials for Drug Delivery

The current study sought to create graphene oxide-based superstructures for gastrointestinal drug delivery. Graphene oxide has a large surface area that can be used to load anti-cancer drugs via non-covalent methods such as surface adsorption and hydrogen bonding. To enhance the bio-applicability of graphene oxide, nano-hybrids were synthesized by encapsulating the graphene oxide into calcium alginate hydrogel beads through the dripping-extrusion technique. These newly developed bio-nanocomposite hybrid hydrogel beads were evaluated in structural analysis, swelling study, drug release parameters, haemolytic assay, and antibacterial activity. Doxorubicin served as a model drug. The drug entrapment efficiency was determined by UV-spectroscopy analysis and was found to be high at ⁓89% in graphene oxide hybrid hydrogel beads. These fabricated hydrogel beads ensure the drug release from a hybrid polymeric matrix in a more controlled and sustained pattern avoiding the problems associated with a non-hybrid polymeric system. The drug release study of 12 h shows about 83% release at pH 6.8. In vitro drug release kinetics proved that drug release was a Fickian mechanism. The cytotoxic effect of graphene oxide hybrid alginate beads was also determined by evaluating the morphology of bacterial cells and red blood cells after incubation. Additionally, it was determined that the sequential encapsulation of graphene oxide in alginate hydrogel beads hides its uneven edges and lessens the graphene oxide's negative impacts. Also, the antibacterial study and biocompatibility of fabricated hydrogel beads made them potential candidates for gastrointestinal delivery.

Recent Advances in Macroporous Hydrogels for Cell Behavior and Tissue Engineering

Hydrogels have been extensively used as scaffolds in tissue engineering for cell adhesion, proliferation, migration, and differentiation because of their high-water content and biocompatibility similarity to the extracellular matrix. However, submicron or nanosized pore networks within hydrogels severely limit cell survival and tissue regeneration. In recent years, the application of macroporous hydrogels in tissue engineering has received considerable attention. The macroporous structure not only facilitates nutrient transportation and metabolite discharge but also provides more space for cell behavior and tissue formation. Several strategies for creating and functionalizing macroporous hydrogels have been reported. This review began with an overview of the advantages and challenges of macroporous hydrogels in the regulation of cellular behavior. In addition, advanced methods for the preparation of macroporous hydrogels to modulate cellular behavior were discussed. Finally, future research in related fields was discussed.

Progress in the Application of Food-Grade Emulsions

The detailed investigation of food-grade emulsions, which possess considerable structural and functional advantages, remains ongoing to enhance our understanding of these dispersion systems and to expand their application scope. This work reviews the applications of food-grade emulsions on the dispersed phase, interface structure, and macroscopic scales; further, it discusses the corresponding factors of influence, the selection and design of food dispersion systems, and the expansion of their application scope. Specifically, applications on the dispersed-phase scale mainly include delivery by soft matter carriers and auxiliary extraction/separation, while applications on the scale of the interface structure involve biphasic systems for enzymatic catalysis and systems that can influence substance digestion/absorption, washing, and disinfection. Future research on these scales should therefore focus on surface-active substances, real interface structure compositions, and the design of interface layers with antioxidant properties. By contrast, applications on the macroscopic scale mainly include the design of soft materials for structured food, in addition to various material applications and other emerging uses. In this case, future research should focus on the interactions between emulsion systems and food ingredients, the effects of food process engineering, safety, nutrition, and metabolism. Considering the ongoing research in this field, we believe that this review will be useful for researchers aiming to explore the applications of food-grade emulsions.

Biodegradable floating hydrogel baits as larvicide delivery systems against mosquitoes

Biological methods for mosquito larvae control are completely biodegradable and have null or limited effects on nontarget organisms. However, commercially available products have a low residual activity, with the consequent need for multiple applications that inevitably increase costs and the risk of resistance phenomena insurgence. Smart delivery systems made of hydrogels proved their efficacy in increasing the action duration of biolarvicides up to several months, but the lack of an efficient baiting mechanism to strongly attract the target pest remains a problem in practical applications. In this work, we investigated two novel hydrogel-based formulations of completely natural composition for baiting and killing larvae of Aedes albopictus mosquitos. The proposed materials consist of charged crosslinked polysaccharides (chitosan and cellulose) and are specifically manufactured to float in water, simulating organic matter usually present at breeding sites. Within the hydrogels' matrix, yeast colonies of Saccharomyces cerevisiae were embedded as phagostimulants alongside a biolarvicide (Bacillus thuringiensis var. israelensis (Bti)). Despite the similar chemical nature and structure, chitosan-based hydrogels exhibited a markedly superior baiting potential compared to those made of cellulose and also succeeded in efficiently killing mosquito larvae just after a few hours from administration. We are confident that the proposed smart delivery hydrogel made of chitosan can be an enabling tool to attract mosquito larvae towards biopesticides of different nature without delocalizing active ingredients away from the breeding site and to simultaneously increase their residual activity, thus holding the potential of minimizing environmental pollution related to pest control and vector-borne disease prevention.

Nanoencapsulation of essential oils from industrial hemp (Cannabis sativa L.) by-products into alfalfa protein nanoparticles

Essential oils of industrial hemp (Cannabis sativa L.) by-products (HBEO) were characterized by gas chromatography-mass spectrometry (GC-MS); then, encapsulated in alfalfa protein isolate nanoparticles (API-NPs) as a novel nanocarrier. A desirable retention (45.5-63.4%) of HBEO within API-NPs was confirmed. These nanoparticles exhibited a shrunk and globular shape with a size range of 156.9-325.9 nm as indicated by dynamic light scattering (DLS), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Furthermore, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and thermal analyses corroborated that HBEO was successfully encapsulated within API NPs in an amorphous form without specific chemical interaction with the carrier matrix. The antioxidant activity of loaded HBEO into API-NPs was higher than free HBEO implying that encapsulation of HBEO in API-NPs was an efficient strategy for improving its stability and functionality. HBEO-loaded API-NPs is a promising candidate to be used in future foods and supplements for novel applications.

Gel Carriers for Plant Extracts and Synthetic Pesticides in Rodent and Arthropod Pest Control: An Overview

Insecticides and rodenticides form the basis of integrated pest management systems worldwide. As pest resistance continues to increase and entire groups of chemical active ingredients are restricted or banned, manufacturers are looking for new options for more effective formulations and safer application methods for the remaining pesticide ingredients. In addition to new technological adaptations of mainstream formulations in the form of sprays, fumigants, and dusts, the use of gel formulations is becoming increasingly explored and employed. This article summarizes information on the current and potential use of gel (including hydrogel) and paste formulations against harmful arthropods or rodents in specific branches of pest management in the agricultural, food, stored product, structural wood, urban, medical, and public health areas. Due to the worldwide high interest in natural substances, part of the review was devoted to the use of gels for the formulation of pesticide substances of botanical origin, such as essential or edible oils. Gels as emerging formulation of so called “smart insecticides” based on molecular iRNA disruptors are discussed.

Evaluation of Hydrophilic and Hydrophobic Silica Particles on the Release Kinetics of Essential Oil Pickering Emulsions

Colloidal particle-stabilized emulsions have recently gained increasing interest as delivery systems for essential oils. Despite the use of silica particles in food and pharmaceutical applications, the formation and release of hydrophilic and hydrophobic silica particle-stabilized emulsions are still not well studied. Thus, in this study, the structures of hydrophilic (A200, A380, 244FP, and 3150) and hydrophobic (R202 and R106) silica were deeply characterized using the solid state, contact angle, and other properties that could affect the formation of emulsions. Following that, Mosla chinensis essential oil emulsions were stabilized with different types of silica, and their characteristics, particularly their release behavior, were studied. Fick's second law was used to investigate the mechanism of release. Additionally, six mathematical models were employed to assess the experimental data of release: zero-order, first-order, Higuchi, Hixson-Crowell, Peppas, and Page models. The release mechanism of essential oils demonstrated that diffusion was the dominant mechanism, and the fitting results for the release kinetics confirmed that the release profiles were governed by the Higuchi model. The contact angle and specific surface area were the key properties that affect the release of essential oils from emulsions. Hydrophilic A200 was found to be capable of delivering essential oils more efficiently, and silica particles could be extended to achieve the controlled release of bioactives. This study showed that understanding the impact of silica particles on the release behavior provided the basis for modulating and mapping material properties to optimize the performance of emulsion products.